Light Well Intervention

Light Well InterventionImproving the recovery of hydrocarbons from subsea wells has always been a challenge. . Well intervention and drilling sidetrack wellbores are a means to increase the oil production from existing wells. FMC Technologies has proven technologies and methods which meet the challenges related to increasing oil recovery from subsea wells.

Improve recovery at low cost

Improved return on capital employed

Well intervention immediately improving �productionOperating costs maintained at a low level by �utilizing existing infrastructureLow cost drainage of smaller reservoir pockets �

StatoilHydro

“Light well intervention is vital for StatoilHydro’s IOR ambition of 55% recovery from subsea fields.”

øystein arvid håland, Senior Vice President, Sub surface technology, TNE

Main assembly test of second generation RLWI

RLWI Operations

Typical intervention operations performed on subsea wells are:

Run/pull tubing hanger crown plugs �Run/pull tubing hanger crown plug seat �protectorsRunning caliper/gauging �Running production logging tool �Plugging �Re-perforation of new production �intervalsInstall insert downhole safety valve �

Reducing the cost of such operations is the principal driving force behind the development of the RLWI technology. FMC’s RLWI Technology enables cost-effective intervention operations into existing subsea wells resulting in additional production volumes from mature subsea fields at highly competitive costs for the incremental volumes of oil.

The technology includes a patented lubricator system for inserting downhole tool packages into the wellbore under full pressure and without taking hydrocarbons back to the vessel. All equipment to connect to and control the subsea well is deployed from the lower cost dynamically positioned monohull vessel without using a drilling or workover risers and anchors.

Second generation lubricator systemDesign criteria:

Subsea flushing of hydrocarbons from �lubricator to wellSubsea closed hydraulic systems �Subsea grease injection pump and reservoir �All-electric control system with subsea �hydraulic power generationConform to relevant API and ISO standards. �

Riserless Light Well Intervention stack up

www.fmctechnologies.com/subsea

Key Facts Light Well Intervention

Increases recovery from subsea wells �

- creating added values

Is cost effective �

Releases rig for drilling �

Through Tubing Rotary Drilling (TTRD) enables efficient drilling, intervention and completion of existing wells through existing subsea completion systems. The TTRD system is currently designed for use on Horizontal Subsea trees; however, the TTRD system will be upgraded for Vertical Subsea trees. The installation is based on guide wires and is run with water based hydraulic fluid; however, the system can interface mineral based hydraulic oil systems.

Traditional TTRD operations have been performed with traditional Blow Out Preventer (BOP) with Marine Riser tied back to surface using heavy intervention vessels; however, the system still requires a completion riser in order to conduct well intervention.

For further optimization a TTRD system with a high pressure riser was developed which utilizes one system for both drilling and well intervention. A Surface BOP (SBOP) with pipe RAM’s and annular preventer is connected to the Marine Riser Slip Joint, providing functional requirements for drilling. In intervention mode high pressure riser joints are stabbed through the Slip Joint and are connected in the top of the SBOP, allowing high pressure conduit to the Surface Flow Tree.

Through Tubing Rotary Drilling

TTRD subsea equipment used for sidetrack drilling

ReferencesFMC has been involved in rigless well intervention since 2003 and has performed operations for the following operators:

Nexen UK �Chevron UK �StatoilHydro �

The second generation RLWI system is planned to start in 2008 for BP UK and with a second system for StatoilHydro.

The TTRD system does not utilize a conventional BOP in any of the operation modes and medium duty intervention vessels can be employed for these operations.

The TTRD system is able to operate in the following modes:

Through Tubing Drilling through a high �pressure riserAll types of wire line operations carried �out by conventional braided wire (mono-conductor) or slicklineCoil Tubing operation �Well stimulation �Through tubing completion �Well testing and clean up �

Main assembly test of second generation RLWI

The Surface BOP, which can be lowered through rotary, makes drilling through HP riser possible

FMC Technologies A

ugust 2008 - 3D illustrations by Industriell D

okumentasjon - print by Prinfo V

anberg

FMC Technologies1777 Gears RoadHouston TX 77067USAPhone: +1 281 591 4000

FMC TechnologiesP.O. Box 1012NO-3601 KongsbergNorwayPhone: +47 3228 6700www.fmctechnologies.com/subsea